Packages used for storing, dispensing and measuring pourable contents such as liquid detergents or fine grained powders are frequently plagued with the problems of leakage and dripping during shipping and storage and in connection with use of the package to dispense the contents. Various constructions for such packages have been adopted to alleviate the problem of leakage and dripping with only limited success.
For example, U.S. Pat. No. 4,550,862 to Barker et al. discloses a Liquid Product Pouring and Measuring Package with a Self Draining Feature having a drainback well and a closure used as a measuring cap. Liquid stored in the package bottle or remaining in the measuring cap can flow around the single wall of the measuring cap between the threads that join the closure and transition collar of the bottle, and collect on the exterior of the package. The package disclosed and claimed by Barker has been found to require the inclusion of a separate gasket disposed between the transition collar and neck of the bottle. Similar constructions wherein liquid in a bottle, or its residue intended to flow from a cap through a drainback well, can instead flow around and to the exterior of the single wall of the cap are disclosed in several patents granted to J. G. Livingstone, including U.S. Pat. No. 2,851,196 for an Adapter, U.S. Pat. No. 2,848,142 for a Container, U.S. Pat. No. 2,763,403 for Fittings, U.S. Pat. No. 2,743,844 for Pouring Spout with Cap and Drip Return, U.S. Pat. No. 2,690,281 for Capped Package with Adapter, and U.S. Pat. No. 2,601,040 for Fitting and Sealing Means Therefor.
U.S. Pat. No. 4,128,189 to Baxter for a Device for Improving the Pourability of Fluids and Also Forming an Improved Closure for a Container of Such Fluids discloses the use of a separate cap and measuring cup which is more complex and costly and less convenient than a single measuring closure.
The use of a dual walled cap to improve the seal on a bottle is disclosed in U.S. Pat. No. 2,061,685 to Wheaton for a Closure. However, Wheaton makes no provision for the use of his cap to prevent leakage in a container having a spout with a drainback feature.
There is provided a device including a measuring cap in Japanese Utility Model Publication No. 54-22525. The device is adapted to drop a measuring cylinder fitted loosely in a bottle mouth onto a cap top sheathing. Thus, a relatively large capacity can be given to the measuring cylinder and residual liquid in the cap will never drip to an outer surface of the bottle when it is again fitted on the mouth cylinder.